PROJECT SUMMARY/ABSTRACT TR&D1 is responsible for the polarizer instrumentation and the MRI acquisition hardware/software required for all hyperpolarized 13C MRI studies performed in this P41 Center housing five dissolution DNP polarizers. All technology developments are driven by the 10 Collaborative Projects with iterative push-pull optimization and user training. These technology resources are then utilized by the 8 Service Projects (6 extramural) and the general scientific community with feedback on performance, quality of training, and ease of dissemination. In the inaugural funding cycle, TR&D1 oversaw new polarizer installation/development to enable and improve the hyperpolarizations required for all CP's and TR&D's, developed new MR sequences for preclinical studies driven by CP's and TR&D2 needs, and facilitated the first human clinical trial with recent preliminary translation work driven by the new CP's that include future clinical research (CP3,6,9,10). We have also worked closely with TR&D3 personnel to create and test new analysis methods to reconstruct, analyze and visualize the new HP 13C MRI techniques through this project. Also a major focus in the current and proposed renewal project is the training of new users (both intra- & extramural and facilitating the dissemination and widespread use of TR&D1 technology. Aim 1: Polarizer Instrumentation Development and Testing. In this aim new DNP/dissolution hardware and methods will be developed for Oxford Instruments HyperSense DNP polarizers, HyperSense Testbed polarizer, the POC polarizer used in the first Phase 1 Clinical Trial, and the GE SpinLab multi-sample polarizer. Aim 2: Preclinical HP 13C MRI Technology Development. In vivo hyperpolarized 13C MRI requires specialized hardware and MR sequences for optimal animal studies. Based on extensive preliminary work, Drs. Vigneron's and Larson's groups will develop specialized HP MR sequences optimized for performance, reliability, and ease of use in collaboration with preclinical CP1-8 investigators and Dr. Nelson TR&D3 analysis technique development group. Aim 3: New Acquisition Technology for Clinical Translation of HP 13C MRI. Driven by CP projects proposing human studies and with the input of the Translation Advisory Committee, new hardware/software will be developed to enable future novel HP 13C MRI clinical research studies with push-pull iterative optimization. This aim will also include training, dissemination, and input/feedback from SP3 and other sites proposing future patient HP 13C MRI.